PRB: TAPI Country IDs Can Change With Operating System Upgrade or Service Pack (281726)

CAUSE

For most countries, the country ID is the same as the E.164 country code. The country ID is different only in cases in which the country code is shared by multiple countries. For example, all countries in North America and the Caribbean share country code "1". In such cases, the country IDs for the countries that share the country code usually consist of the country code followed by a numeric suffix. The exception is that the largest country among those that share the country code has a country ID equivalent to the country code.

Since most countries do not want to change country codes, the country list tends to be stable, with few changes from year to year. Although the intention is that country IDs are permanent and will not arbitrarily change across versions of Windows, changes do occur. Significant changes have occurred over the past few years with the division of Czechoslovakia, Yugoslavia, and the Soviet Union, and the merger of East Germany and West Germany. Some countries that previously shared codes have implemented, or are planning to implement, separate codes, such as Monaco, Liechtenstein, Andorra, San Marino, and the Vatican. When such changes occur, the country list is updated to track them, and this can result in country IDs being added, deleted, or changed.